11.08.12 9:45 AM ET

Jeff Goldblum cannot sit still. He gyrates back and forth in his plush red-velvet chair in his dressing room. His long hands work in circular motions around his torso for emphasis. He is talking fervently about Leonard’s gut.

Leonard is the egomaniacal writing guru Goldblum plays in Smash creator Theresa Rebeck’s play Seminar, now playing at the Ahmanson Theatre in Los Angeles. Leonard critiques his students in savage language, telling one that he is a “talented nobody,” and pushes them to do something with their lives. Without experience, Leonard tells his mortified students, writing becomes a “soul-sucking waste of words.”

On this particular night, Goldblum decided that Leonard was feeling more than the usual impatience with his four students’ preciousness.

“I wanted to emphasize the effort that they were not doing,” Goldblum said backstage after the show, his hands gesticulating wildly. “The rents in New York or how to get ahead in a little writer’s colony or sniping with each other or criticizing old writers—that ain’t what they should be devoting their passions to. It should be about telling stories that are relevant, serve, and minister.”

Even though Goldblum has been with Leonard for more than seven months now—first in a Broadway production and now in Los Angeles through November 18—the actor finds there is still more to pick off the meaty role. Nearly 30 years after he starred as the neurotic tabloid reporter Michael Gold in The Big Chill, Goldblum is in a place professionally where he can take risks, run the gamut of interpretation without worrying too much about the critics.

“Acting is terrific and more than ever delicious to me. I go wherever the best material is,” he said, his long feet firmly planted in neon-green and orange sneakers. “Across the board now, what am I trying is to be in the moment and enjoy myself as presently as I can. I don’t know what more there is to accomplish except that.”

Not only has he been performing on stage in Los Angeles, London, and New York, but he is seen frequently on television, including a turn on Glee as a gay dad and the artisan knot salesman Alan on Portlandia. In January he will go to Germany to star in Wes Anderson’s latest feature film, The Grand Budapest Hotel.

The 60-year-old actor/musician, who always brings a keyboard to his dressing room, has thrived playing eccentric geniuses who are irresistible in their charm. He has become an unlikely sex symbol, in all his gangly nerdiness (and early freaky roles like The Fly). (He even had a stalker who was arrested in Los Angeles after coming to his performance of Seminar). In person, he is disarming and yet manic. He is unguarded and uses words like “stumblebummyness” and “nincompoopery.”

Midstream in conversation backstage, he falls into “drunk Jeff Goldblum” mode, with his deep voice suddenly slowing to a slurring halt. The strange thing is, it’s unintentional. He is not drunk and after a few sentences, he picks up speed again and offers no explanation.

And yet the videos of a “drunk Jeff Goldblum” have become something of an Internet phenom. YouTube is full of the ads where Goldblum is pitching Paypal or Apple computers in a slowed-down audio track that makes him sound wasted. He takes it in stride.

“I got a kick out of the Apple commercials,” he said, laughing.

He also was prematurely killed off by blogger in June 2009 who Tweeted (as a prank) that Goldblum had fallen off a cliff while filming in New Zealand. But soon, news channels all over the world picked up the story and suddenly Goldblum found himself issuing a press release and having to deny he was dead on the Stephen Colbert show. He admits it was a little funny … but not really.

“That was bizarre,” he said, his brown eyes getting wide behind his tortoise-shell glasses. “It was not so nice on the day that it happened.”

He is very much alive and seems at ease with his place in the world. When he speaks of Leonard, it is hard not to see some of it also applies to him. He has, for the most part, found a balance between the “whoring” of working in Hollywood—as Leonard eloquently states—and doing art for art’s sake. Status and critics don’t seem to matter as much as his own opinion of himself.

“You cannot open yourself up to everybody’s opinion, otherwise you would be lost,” he said. “So you do develop your own standards about what the hell you are trying to do because this is not an empirical science. There ain’t no goal line. It’s everybody’s opinion about whether you are cutting the mustard or not,” and then to end the thought with a non sequitur: “Or skinning the cat.”